Retrofitting Old Preamp with Motorized Volume Control

[Jmo]

Hello, first post here. I can't seem to find on a thread on my exact topic, which seems fairly straightforward. As the title says, I want to update my old NAD 1020 with a motorized volume/remote. Installing the volume control itself seems straightforward but I'm stumped about how to get power to it. I want to tap into the preamp power supply and connect an LM317 for the 5 volts needed but am not sure what the best way to do this is (or even if this is the best option). I can post a schematic if that will help answer the question.

Thanks--John

 

[Bob Richards]

You would need to post a schematic. What remote control and associated electronics are you planning to use?

 

[Vinster]

Service manual with Schematic for your pre-amp is available for free here; NAD 1020B Manual - Stereo Pre Amplifier - HiFi Engine

There isn't any 5v power in there right now, only +23.3v and -20.2v. I'd suggest if there is room in the amp housing to solder in and piggy back on the 120VAC switched output a small USB type power supply for your required 5v.

Others may have a better suggestion, but this is where I would start.

Post pictures as I'm interested in this project as well.

Vin

 

[Jmo]

Thanks for the replies. I'm considering an ALPS 27K or maybe something like this:

New Lite MV02 4 Way Input Motorized Remote Volume Control | eBay

Schematics are attached.

 

[rsavas]

Cheapest solution is to pick off the AC output of the transformer secondary, after the fuses. Add a power resistor in series to drop the supply down to the required input range.
The MV02 requires Power supply : AC9-12V, 3Amp
What documentation came with MV02? post it.
You will lose loundness compensation since the Alps 27K pot does not have a loundness tap!

 

[Vinster]

Sorry I missed your reply. I agree with rsavas. if you need 12v then either a power resistor or a voltage divider circuit from the main fused power to get to 12v.

I can't find a schematic for that volume controller. says it comes with a drawing, but I'd want to see it to make sure you can make that kit work if I were you. Maybe contact the seller to get a copy.

The other is, will that large board fit where the original volume control is? that's a big board.

Vin

 

[Jmo]

Thanks for these replies. Yeah, it looks like MV02 won't work; not enough space behind the existing volume control.

 

[adason]

Thanks for the replies. I'm considering an ALPS 27K or maybe something like this:

New Lite MV02 4 Way Input Motorized Remote Volume Control | eBay

Schematics are attached.

this works really well, I used this remote twice before, recommended

 

[Bob Richards]

this works really well, I used this remote twice before, recommended

Thanks much for this rec. I've been trying to find something like this for a while, and this one looks like the best I've seen. I wonder if there will be duty fees shipping to the U.S. (?)

 

[Bare]

Dunno I had a remote/motorised volume selector on a previous amp.
I realised soon enough that; because I could diddle with it from my chair .. I did.
Much like the TV remote it just encouraged constant/obsessive fiddling.
I eventually 'lost' that amp and it's remote... Happily
Take care in what You wish for

 

[AndrewT]

I used the MV02

It works well.
Couple of quirky bits that I recall.
When adjusting the volume, i.e. when the motor is turning, there is some quiet digital clicking coming through the audio channels.
When changing channels the software turns the volume all the way down to zero, every time.
You can interupt this by pressing a button (can't remember which one, since I gave this amplifier away as a Birthday present).

 

[adason]

You can disable that function...there are some pins to connect on the board. That is annoying but luckily only optional...since you no longer have it, i will not bother opening my preamp, just as info for others.